All four — joined in the Australian conference by Japan's Sunwolves — have reason for optimism and skepticism. The Rebels are the most intriguing case, having absorbed 12 players and coach David Wessels from the other side of the Nullarbor.
South African Wessels now has a star-studded squad at his disposal — and Melbourne the best chance in their history to break their finals duck — but with new combinations to be rolled out in just about every part of the team, they may be a work in progress through the early part of the season.
The Brumbies also have a new coach in Dan McKellar, who has succeeded Stephen Larkham after his move to a full-time Wallabies role.
David Pocock's return from a one-year sabbatical is a major boost but the reigning Australian conference champions.
It's been a summer of upheaval at Ballymore, where another rookie coach — Brad Thorn — has laid down the law. Quade Cooper and Nick Frisby have been banished, Karmichael Hunt remains in limbo, and Thorn will lean heavily on the raw talents from his NRC-winning Queensland Country squad to bring the Reds out of the doldrums.
Daryl Gibson, meanwhile, must do the same with the Waratahs after embarrassing home losses last year to the Kings and Jaguares.
His coaching career is on the line but Kurtley Beale's comeback to Super Rugby and new signings such as Curtis Rona and a reborn Rob Simmons should help turn things around.